7,100 bodies are buried at the former Eloise mental hospital in Westland, near Detroit. But you'd never guess that from walking around the property.

That’s because the cemetery, which was never meant to be a traditional cemetery, looks more like an empty field. But look down, and you'll discover rows and rows of cement markers the size of large bricks with numbers stamped into them.

“This person buried here is number 5,632,” says Felicia Sills, as she gets on her knees and gently traces her finger over each number.